A retrospective single cohort study on the 5–13 year clinical outcomes of implant-supported cross-arch fixed dental prostheses with monolithic zirconia-based frameworks

Abstract

Purpose: To investigate the mid-to-long term clinical outcomes of the implant-supported cross-arch fixed dental prostheses (IFCDPs) with monolithic zirconia-based frameworks and related risk factors of success and survival. Materials and Methods: This retrospective study encompassed individuals exhibiting terminal dentition or edentulism in the maxilla and/or mandible who underwent treatment involving IFCDPs with monolithic zirconia frameworks. Inclusion criteria required a documented follow-up period of at least five years post-definitive prosthesis delivery. Evaluation of outcomes focused on the survival rates of implant and prosthesis, along with the incidence of biological and technical complications. The mixed-effects Cox regression model was employed to analyze the risk factors associated with prosthesis failure and peri-implantitis. Results: A cohort of 47 patients, consisting of 14 women and 33 men with a mean age of 55.2 ± 12.5 years (range: 25–83), was included in this study. The mean follow-up period was 71.6 ±13.2 months (mean ± SD, range: 60–147). A total of 51 cross-arch prostheses supported by 302 implants, distributed between the maxilla (27 prostheses) and mandible (24 prostheses), were assessed. By the end of the follow-up period, 289 (97.64%) of the 302 implants remained functional. Peri-implantitis was observed in 27 implants (24 in mandible), yielding an overall implant-related success rate of 91.06%. Nine frameworks experienced fractures (eight in mandible), resulting in an overall prosthesis-related survival rate of 82.35%. Subsequent analysis revealed the mandible to be a significant risk factor for framework fracture (HR = 11.64, p = 0.024) and peri-implantitis (HR = 10.88, p = 0.003). Conclusions: The implant-supported cross-arch fixed dental prostheses featuring monolithic zirconia-based frameworks demonstrated favorable clinical outcomes throughout a 5–13-year observation period. Notably, in the design of monolithic zirconia-based framework prostheses, the mandible emerged as a significant risk factor for framework fractures and an independent risk factor for peri-implantitis.